German Registry Data Evaluated for Trends in Patient Safety of AAA Repair

February 7, 2017—German registry data on 36,594 procedures to repair nonruptured abdominal aortic aneurysms (AAA) were published by Matthias Trenner, MD, et al online in the European Journal of Vascular and Endovascular Surgery (EJVES). The study's goal was to determine whether patient safety for nonruptured AAA repair has changed between 1999 and 2010 in a large German cohort.

The data source was the prospective quality assurance registry of the German Vascular Society from 1999 to 2010. Patient characteristics, surgical techniques (open aortic repair [OAR] and endovascular aortic repair [EVAR]), procedural time, and outcomes including the length of hospital stay (LOS), were analyzed using the Cochran–Armitage test for binary parameters and Spearman's correlation coefficient for quantitative parameters.

As summarized in EJVES, the investigators evaluated a total of 36,594 operations (23,037 OAR; 13,557 EVAR) for infrarenal nonruptured AAA in 201 hospitals in Germany. Patients' mean age increased from 69.6 to 72.0 years (P < .001). The rate of patients with American Society of Anesthesiologists scores of 3 or 4 also increased (P < .001).

The investigators reported that use of EVAR increased (1999: 16.7%; 2010: 62.7%; P < .001), and since 2009, EVAR has been more frequently used than OAR. 

The overall in-hospital mortality decreased from 3.1% in 1999 to 2.3% in 2010 (P < .001). There were no temporal trends for mortality rates for EVAR (P = .233) or OAR (P = .281) when considered separately. Cardiac (1999: 8.1%; 2010: 5.1%; P < .001) and pulmonary (1999: 7.8%; 2010: 4.8%; P < .001) complications decreased. The rate of postoperative renal failure increased (1999: 3.6%; 2010 4.1%; P = .017), without increasing the rate of patients needing dialysis (1999: 1.7%; 2010: 1.7%; P = .171). The median LOS decreased from 17 days in 1999 to 10 days in 2010 (P < .001).

The investigators concluded that this study shows significantly improved postprocedural, in-hospital outcomes and decreased use of resources for nonruptured AAA repair. This trend can probably be attributed to the implementation of EVAR as a standard technique, but some trends could also possibly be explained by a change in the remuneration system. The main limitation of the registry is the lack of internal and external validation. However, in-hospital patient safety for AAA repair seems to have improved significantly in the participating hospitals, noted the investigators in EJVES.